Peristaltic pumps are well known, having various configurations and applications. One configuration of a peristaltic pump has five primary elements comprising a rotor assembly, an occlusion bed, a tubing retainer system, tubing and a power source to drive the rotor assembly. The rotor assembly may be comprised of rollers, each having the same diameter and equally spaced circumferentially. The axis of each roller is the same distance from, and parallel to the axis of the driven shaft of the rotor assembly. The occlusion bed provides a surface for the rollers of the rotor assembly to compress the tubing against, while the tubing retainer system captures the tubing and holds it in position. The tubing must be made of a material with sufficient elastic properties to recover its shape after being compressed by the rollers.
During operation, the pump functions by compressing the tubing between the rotor and the occlusion bed along the rollers radial path. This compression of the tubing gives the pump its positive displacement action, moving the fluid in the tube while preventing backflow. The retainers hold the tubing in position at the entrance and exit of the roller/occlusion bed path. As the rollers move against the tubing, a pushing force is transmitted to the tube.
Peristaltic pumps having the foregoing configuration have been successfully used commercially in a wide variety of applications. However, pumps of this type can provide various manufacturing and/or installation challenges. For example, the consequence of the force transmitted to the tube can cause the tubing on the output side of the roller path to bunch in the space between the occlusion bed and its retainer. The only solution to overcome the bunching problem is proper installation of the tubing. Unfortunately, there is a certain amount of learned technique required. The technique, acquired only by experience, is needed to ensure the proper amount of tubing is placed between the retainers. The required length of tubing between the retainers tends to be subjective and is therefore a matter of opinion by a new user during installation. Additionally, the amount of tension in the tubing required for proper operation varies with the different tubing materials.
The industry standard practice to accomplish proper tube positioning is to provide a tubing “set”. Tubing sets consist of a given length of tube with attached retaining features on each end that interface with the pump retainers. For example, each end of the tube may be inserted into a coupling which is held in place by a tube retaining device of the pump. This tubing set must be then coupled with other lengths of the tubing to complete the intended circuit.
Based on the foregoing, it may be appreciated that the potential drawbacks of known peristaltic pumps of the type discussed include improper tube installation and the requirement for multiple connections precluding the use of a single length of tubing in the fluid flow circuit thereby requiring additional assembly time.